Class Inet4Address
- All Implemented Interfaces:
Serializable
Textual representation of IPv4 addresses
Textual representation of IPv4 address used as input to methods takes one of the following forms:
d.d.d.dd.d.dd.dd
When four parts are specified, each is interpreted as a byte of data and assigned, from left to right, to the four bytes of an IPv4 address.
When a three part address is specified, the last part is interpreted as a 16-bit quantity and placed in the right most two bytes of the network address. This makes the three part address format convenient for specifying Class B network addresses as 128.net.host.
When a two part address is supplied, the last part is interpreted as a 24-bit quantity and placed in the right most three bytes of the network address. This makes the two part address format convenient for specifying Class A network addresses as net.host.
When only one part is given, the value is stored directly in the network address without any byte rearrangement.
For example, the following (decimal) forms are supported by the methods
ofLiteral(String) and InetAddress.getByName(String)
which are capable of parsing textual representations of IPv4 addresses:
// Dotted-decimal 'd.d.d.d' form with four part address literal
InetAddress.getByName("007.008.009.010"); // ==> /7.8.9.10
InetAddress.getByName("127.0.1.1"); // ==> /127.0.1.1
// Dotted-decimal 'd.d.d' form with three part address literal,
// the last part is placed in the right most two bytes
// of the constructed address
InetAddress.getByName("127.0.257"); // ==> /127.0.1.1
// Dotted-decimal 'd.d' form with two part address literal,
// the last part is placed in the right most three bytes
// of the constructed address
Inet4Address.ofLiteral("127.257"); // ==> /127.0.1.1
// 'd' form with one decimal value that is stored directly in
// the constructed address bytes without any rearrangement
Inet4Address.ofLiteral("02130706689"); // ==> /127.0.1.1
The above forms adhere to "strict" decimal-only syntax.
Additionally, the ofPosixLiteral(String)
method implements a POSIX inet_addr compatible "loose"
parsing algorithm, allowing octal and hexadecimal address segments.
Please refer to
RFC 6943: Issues in Identifier Comparison for Security
Purposes. Aside from Inet4Address.ofPosixLiteral(String), all methods only
support strict decimal parsing.
For methods that return a textual representation as output value, the first form, i.e. a dotted-quad string in strict decimal notation, is used.
The Scope of a Multicast Address
Historically the IPv4 TTL field in the IP header has doubled as a multicast scope field: a TTL of 0 means node-local, 1 means link-local, up through 32 means site-local, up through 64 means region-local, up through 128 means continent-local, and up through 255 are global. However, the administrative scoping is preferred. Please refer to RFC 2365: Administratively Scoped IP Multicast- Since:
- 1.4
- External Specifications
- See Also:
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Method Summary
Modifier and TypeMethodDescriptionbooleanCompares this object against the specified object.byte[]Returns the raw IP address of thisInetAddressobject.Returns the IP address string in textual presentation form.inthashCode()Returns a hashcode for this IP address.booleanUtility routine to check if the InetAddress is a wildcard address.booleanUtility routine to check if the InetAddress is a link local address.booleanUtility routine to check if the InetAddress is a loopback address.booleanUtility routine to check if the multicast address has global scope.booleanUtility routine to check if the multicast address has link scope.booleanUtility routine to check if the multicast address has node scope.booleanUtility routine to check if the multicast address has organization scope.booleanUtility routine to check if the multicast address has site scope.booleanUtility routine to check if the InetAddress is an IP multicast address.booleanUtility routine to check if the InetAddress is a site local address.static Inet4AddressCreates anInet4Addressbased on the provided textual representation of an IPv4 address.static Inet4AddressofPosixLiteral(String posixIPAddressLiteral) Creates anInet4Addressbased on the provided textual representation of an IPv4 address in POSIXinet_addrcompatible form.Methods declared in class java.net.InetAddress
getAllByName, getByAddress, getByAddress, getByName, getCanonicalHostName, getHostName, getLocalHost, getLoopbackAddress, isReachable, isReachable, toString
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Method Details
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ofLiteral
Creates anInet4Addressbased on the provided textual representation of an IPv4 address.If the provided IPv4 address literal cannot represent a valid IPv4 address an
IllegalArgumentExceptionis thrown.This method doesn't block, i.e. no reverse lookup is performed.
- Parameters:
ipv4AddressLiteral- the textual representation of an IPv4 address.- Returns:
- an
Inet4Addressobject with no hostname set, and constructed from the provided IPv4 address literal. - Throws:
IllegalArgumentException- if theipv4AddressLiteralcannot be parsed as an IPv4 address literal.NullPointerException- if theipv4AddressLiteralisnull.- Since:
- 22
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ofPosixLiteral
Creates anInet4Addressbased on the provided textual representation of an IPv4 address in POSIXinet_addrcompatible form.The method
ofPosixLiteralimplements POSIXinet_addrcompatible parsing algorithm, allowing octal and hexadecimal address segments."0"is the prefix for octal numbers,"0x"and"0X"are the prefixes for hexadecimal numbers. Non-zero address segments that start from non-zero digits are parsed as decimal numbers. The following (non-decimal) forms are supported by this method:// Dotted-quad 'x.x.x.x' form with four part address literal Inet4Address.ofPosixLiteral("0177.0.0.1"); // ==> /127.0.0.1 Inet4Address.ofPosixLiteral("0x7F.0.0.1"); // ==> /127.0.0.1 // Dotted-triple 'x.x.x' form with three part address literal, // the last part is placed in the rightmost two bytes // of the constructed address Inet4Address.ofPosixLiteral("0177.0.0402"); // ==> /127.0.1.2 Inet4Address.ofPosixLiteral("0x7F.0.0x102"); // ==> /127.0.1.2 // Dotted-double 'x.x' form with two part address literal, // the last part is placed in the rightmost three bytes // of the constructed address Inet4Address.ofPosixLiteral("0177.0201003"); // ==> /127.1.2.3 Inet4Address.ofPosixLiteral("0x7F.0x10203"); // ==> /127.1.2.3 Inet4Address.ofPosixLiteral("127.66051"); // ==> /127.1.2.3 // Dotless 'x' form with one value that is stored directly in // the constructed address bytes without any rearrangement Inet4Address.ofPosixLiteral("0100401404"); // ==> /1.2.3.4 Inet4Address.ofPosixLiteral("0x1020304"); // ==> /1.2.3.4 Inet4Address.ofPosixLiteral("16909060"); // ==> /1.2.3.4If the provided IPv4 address literal cannot represent a valid IPv4 address in POSIX form an
IllegalArgumentExceptionis thrown.This method doesn't block, i.e. no hostname lookup is performed.
- API Note:
- This method produces different results compared to ofLiteral(java.lang.String)
when
posixIPAddressLiteralparameter contains address segments with leading zeroes. An address segment with a leading zero is always parsed as an octal number by this method, therefore0255(octal) will be parsed as173(decimal). On the other hand,Inet4Address.ofLiteralignores leading zeros, parses all numbers as decimal and produces255. Where this method would parse0256.0256.0256.0256(octal) and produce174.174.174.174(decimal) in four dotted quad notation,Inet4Address.ofLiteralwill throwIllegalArgumentException. - Parameters:
posixIPAddressLiteral- a textual representation of an IPv4 address.- Returns:
- an
Inet4Addressobject with no hostname set, and constructed from the provided IPv4 address literal. - Throws:
IllegalArgumentException- if theposixIPAddressLiteralcannot be parsed as an IPv4 address literal.NullPointerException- if theposixIPAddressLiteralisnull.- Since:
- 23
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isMulticastAddress
public boolean isMulticastAddress()Utility routine to check if the InetAddress is an IP multicast address. IP multicast address is a Class D address i.e first four bits of the address are 1110.- Overrides:
isMulticastAddressin classInetAddress- Returns:
- a
booleanindicating if the InetAddress is an IP multicast address
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isAnyLocalAddress
public boolean isAnyLocalAddress()Utility routine to check if the InetAddress is a wildcard address.- Overrides:
isAnyLocalAddressin classInetAddress- Returns:
- a
booleanindicating if the InetAddress is a wildcard address.
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isLoopbackAddress
public boolean isLoopbackAddress()Utility routine to check if the InetAddress is a loopback address.- Overrides:
isLoopbackAddressin classInetAddress- Returns:
- a
booleanindicating if the InetAddress is a loopback address; or false otherwise.
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isLinkLocalAddress
public boolean isLinkLocalAddress()Utility routine to check if the InetAddress is a link local address.- Overrides:
isLinkLocalAddressin classInetAddress- Returns:
- a
booleanindicating if the InetAddress is a link local address; or false if address is not a link local unicast address.
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isSiteLocalAddress
public boolean isSiteLocalAddress()Utility routine to check if the InetAddress is a site local address.- Overrides:
isSiteLocalAddressin classInetAddress- Returns:
- a
booleanindicating if the InetAddress is a site local address; or false if address is not a site local unicast address.
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isMCGlobal
public boolean isMCGlobal()Utility routine to check if the multicast address has global scope.- Overrides:
isMCGlobalin classInetAddress- Returns:
- a
booleanindicating if the address has is a multicast address of global scope, false if it is not of global scope or it is not a multicast address
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isMCNodeLocal
public boolean isMCNodeLocal()Utility routine to check if the multicast address has node scope.- Overrides:
isMCNodeLocalin classInetAddress- Returns:
- a
booleanindicating if the address has is a multicast address of node-local scope, false if it is not of node-local scope or it is not a multicast address
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isMCLinkLocal
public boolean isMCLinkLocal()Utility routine to check if the multicast address has link scope.- Overrides:
isMCLinkLocalin classInetAddress- Returns:
- a
booleanindicating if the address has is a multicast address of link-local scope, false if it is not of link-local scope or it is not a multicast address
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isMCSiteLocal
public boolean isMCSiteLocal()Utility routine to check if the multicast address has site scope.- Overrides:
isMCSiteLocalin classInetAddress- Returns:
- a
booleanindicating if the address has is a multicast address of site-local scope, false if it is not of site-local scope or it is not a multicast address
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isMCOrgLocal
public boolean isMCOrgLocal()Utility routine to check if the multicast address has organization scope.- Overrides:
isMCOrgLocalin classInetAddress- Returns:
- a
booleanindicating if the address has is a multicast address of organization-local scope, false if it is not of organization-local scope or it is not a multicast address
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getAddress
public byte[] getAddress()Returns the raw IP address of thisInetAddressobject. The result is in network byte order: the highest order byte of the address is ingetAddress()[0].- Overrides:
getAddressin classInetAddress- Returns:
- the raw IP address of this object.
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getHostAddress
Returns the IP address string in textual presentation form.- Overrides:
getHostAddressin classInetAddress- Returns:
- the raw IP address in a string format.
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hashCode
public int hashCode()Returns a hashcode for this IP address.- Overrides:
hashCodein classInetAddress- Returns:
- a hash code value for this IP address.
- See Also:
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equals
Compares this object against the specified object. The result istrueif and only if the argument is notnulland it represents the same IP address as this object.Two instances of
InetAddressrepresent the same IP address if the length of the byte arrays returned bygetAddressis the same for both, and each of the array components is the same for the byte arrays.- Overrides:
equalsin classInetAddress- Parameters:
obj- the object to compare against.- Returns:
trueif the objects are the same;falseotherwise.- See Also:
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